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Isolation of bacterial strains able to metabolize lignin from screening of environmental samples
Author(s) -
Taylor C.R.,
Hardiman E.M.,
Ahmad M.,
Sainsbury P.D.,
Norris P.R.,
Bugg T.D.H.
Publication year - 2012
Publication title -
journal of applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 1364-5072
DOI - 10.1111/j.1365-2672.2012.05352.x
Subject(s) - library science , chemistry , computer science
Aims To develop a method to detect bacteria from environmental samples that are able to metabolize lignin. Methods and Results A previously developed UV –vis assay method for lignin degradation activity has been developed for use as a spray assay on agar plates. Nine mesophilic strains were isolated using this method from woodland soil incubated in enrichment cultures containing wheat straw lignocellulose: four M icrobacterium isolates, two M icrococcus isolates, R hodococcus erythropolis (all A ctinobacteria) and two O chrobactrum isolates ( A lphaproteobacteria). Three thermotolerant isolates were isolated from the same screening method applied at 45°C to samples of composted wheat straw from solid‐state fermentation: T hermobifida fusca and two isolates related to uncharacterized species of R hizobiales and S phingobacterium ( B acteroidetes), the latter strain showing tenfold higher lignin degradation activity than other isolates. The isolated strains were able to depolymerize samples of size‐fractionated high molecular weight and low molecular weight K raft lignin, and produced low molecular weight metabolites oxalic acid and protocatechuic acid from incubations containing wheat straw lignocellulose. Conclusions A new method for the isolation of bacteria able to metabolize lignin has been developed, which has been used to identify 12 bacterial isolates from environmental sources. The majority of isolates cluster into the A ctinobacteria and the A lphaproteobacteria. Significance and Impact of the Study Lignin‐degrading bacterial strains could be used to convert lignin‐containing feedstocks into renewable chemicals and to identify new bacterial lignin‐degrading enzymes.